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Common ideas about how cancer develops and spreads can make sense, even if they are scientifically incorrect, especially if those ideas are rooted in old theories. There are some things I can think of. However, incorrect beliefs about cancer can cause unnecessary worry and even interfere with appropriate prevention and treatment decisions. This page provides up-to-date, science-based information about common misconceptions and misconceptions about cancer.
Is cancer a death sentence?
In the United States, the likelihood of dying from cancer has steadily declined since the 1990s. Five-year survival rates for some cancers, such as breast, prostate, and thyroid cancers, are now over 90%. The five-year survival rate for all cancers combined is currently about 69 percent. For more information, see Annual report to the public on the current state of cancer.
However, it is important to note that these percentages are based on data from a large number of people. How long an individual cancer patient lives and whether he or she will die from the disease depends on whether the cancer grows slowly or quickly, how far the cancer has spread within the body, whether there are effective treatments, and the extent of the cancer. It depends on many factors, including how slow your progress is. such as a person's overall health.
Does eating sugar make cancer worse?
No. Studies have shown that cancer cells consume more sugar (glucose) than normal cells, but eating sugar will make your cancer worse, or if you stop eating sugar your cancer will shrink or disappear. There are no studies that say it does. However, a diet high in sugar can contribute to excessive weight gain, and obesity is associated with an increased risk of developing some types of cancer. For more information, see the NCI Fact Sheet on Obesity and Cancer.
Is cancer contagious?
In general, no. Cancer is not a contagious disease that spreads easily from person to person. The only situation in which cancer can spread from person to person is when an organ or tissue is transplanted. People who have received an organ or tissue transplant from a donor who previously had cancer may be at increased risk of developing transplant-related cancer in the future. However, the risk is very low, with about 2 cancers occurring for every 10,000 organ transplants. Doctors avoid using organs or tissue from donors with a history of cancer.
Some people use certain viruses (such as some types of human papillomavirus, or HPV) or bacteria (e.g. Helicobacter pylori). Viruses and bacteria can be spread from person to person, but the cancers they cause cannot be spread from person to person. For more information about cancer-causing viruses and bacteria, see the NCI fact sheet on Helicobacter pylori and cancer and the HPV and cancer and infectious pathogens pages.
Does my attitude, positive or negative, determine my risk of getting or surviving cancer?
To date, there is no convincing scientific evidence linking a person's 'attitude' to the risk of developing or dying from cancer. When you have cancer, it is normal to feel sad, angry, and depressed at times, and to feel positive and upbeat at other times. People with a positive attitude are more likely to maintain social connections and stay active, and physical activity and emotional support may help people cope with cancer. For more information, see the NCI fact sheet on stress and cancer.
Can cancer surgery or tumor biopsy cause cancer to spread within the body?
Surgery is very unlikely to spread cancer to other parts of the body. Following standard procedures, surgeons use special methods and take many steps to prevent the spread of cancer cells during the biopsy or surgery to remove the tumor. For example, if tissue needs to be removed from multiple areas of the body, different surgical instruments are used for each area. To learn more about how cancer spreads in the body, see our page on metastatic cancer.
Does exposure to air make cancer worse?
No, exposure to air does not cause tumors to grow faster or cancer to spread to other parts of the body. To learn more about how cancer spreads in the body, see our page on metastatic cancer.
Do cell phones cause cancer?
No, not according to the best research completed to date. Cancer is caused by genetic mutations, and cell phones emit a type of low-frequency energy that does not damage genes. For more information, see the NCI Fact Sheet on Cell Phones and Cancer Risk.
Do power lines cause cancer?
No, not according to the best research completed to date. Power lines emit both electrical and magnetic energy. Electrical energy emitted by power lines is easily blocked or weakened by walls and other objects. The magnetic energy emitted by power lines is low-frequency radiation that does not damage genes. For more information, see the NCI Fact Sheet on Electromagnetic Fields and Cancer.
Are there any herbal products that can treat cancer?
No, although some research suggests that alternative or complementary therapies, including some herbs, may help patients cope with the side effects of cancer treatment, There are no herbal products proven to be effective. In fact, some herbal products can be harmful if taken during chemotherapy or radiation therapy because they can interfere with the effectiveness of these treatments. Cancer patients should talk to their doctors about complementary and alternative medicine products they may be using, such as vitamins and herbal supplements. For more information, see Complementary and Alternative Medicine.
If someone in my family has cancer, can I get cancer too?
Not necessarily. Cancer is caused by harmful changes (mutations) in genes. Only about 5 to 10 percent of cancers are caused by harmful mutations inherited from both parents. In families with a genetic mutation that causes cancer, more than one family member often develops the same type of cancer. These cancers are called “familial” or “hereditary” cancers.
The remaining 90 to 95 percent of cancers are caused by mutations that occur during a person's lifetime as a natural result of aging and exposure to environmental factors such as cigarette smoke and radiation. These cancers are called “non-hereditary” or “spontaneous” cancers. For more information about your risk of developing cancer, see Genetic Testing for Hereditary Cancer Risk and the NCI Fact Sheet on Cancer Causes and Risk Factors.
If no one in my family has had cancer, does that mean I'm not at risk?
No. According to the latest data, approximately 39 percent of men and women will be diagnosed with cancer at some point in their lives. Most cancers are caused by genetic changes that occur throughout life as a natural result of aging and exposure to environmental factors such as tobacco smoke and radiation. Other factors can also affect your risk of developing cancer, such as what kind of food you eat, how much you eat, and whether you exercise. For more information, see Cancer Causes and Risk Factors.
Do antiperspirants and deodorants cause breast cancer?
No, the best studies to date have found no evidence linking changes in breast tissue to chemicals commonly found in antiperspirants and deodorants. For more information, see the NCI Fact Sheet on Antiperspirants/Deodorants and Breast Cancer.
